Differences between Japan’s most recent coronavirus surge and a wave subdued in the summer are giving lawmakers pause, and forcing experts to adjust their strategies as the country enters winter with a population that’s been counted as the most vulnerable in the world.

At first glance, the wave of cases since the start of November appears similar to the summer jump, which was brought under control with only minor tweaks in policy. But authorities this time are saying to prepare for a "worst-case scenario” as serious cases rise well past the summer peak to a record.

"We have a sense of urgency over the fact that the number of serious cases has risen to almost 500,” health minister Norihisa Tamura said Tuesday. The increase is sending authorities scrambling to ensure there are enough beds and medical practitioners to staff them.